The isopropylamine salt of glyphosate is a known herbicide which is currently registered for such purpose with the Environmental Protection Agency (EPA). Thiocyanates, in general, have found several agricultural applications such as herbicides, crop desiccants and defoliants, adjuvants and the like.
In some cases, active agricultural chemicals have been shown to be more effective in combination than when applied individually. The result is often termed "potentiation" or "synergism" since the combination demonstrates a potency or activity level exceeding that which it would be expected to have, based on a knowledge of the individual potencies of the components.
The present invention resides in the discovery that the herbicidal activity of the isopropylamine salt of glyphosate is markedly enhanced when used in combination with certain thiocyanates, particularly ammonium thiocyanate.